Plant Total Phenol Content Assay Kit (UV Colorimetric Method)

Cat. No.: P1509321

GRADE & PURITY BioReagent

Overview

Plant tissues or fruits contain substances such as anthocyanins, chlorophyll, carotenoids, flavonoids, and phenolics. These substances are closely related to the aging process of fruits and other samples, significantly impacting their processing properties, storage, and nutritional value. Plant phenolics possess free radical‑scavenging, antioxidant, and anti‑aging effects. Due to their high nutritional value and health‑promoting properties, they are widely used in cosmetics, food, medicine, and other fields.

Detection Principle

Total phenols are soluble in organic solvents. Crude extraction of total phenols is performed using an organic solvent. Based on the absorption spectral characteristics of the extract, the absorbance can be measured at 280 nm using a UV spectrophotometer. By comparison with a standard curve, the total phenol content is calculated. This kit is primarily used for the extraction of total phenols from plant tissues or fruits and the quantitative determination of total phenol content. This kit is for research use only and is not suitable for clinical diagnosis or other purposes.

Applicable Samples: Plant tissues, fruits

Reagents, consumables and Equipments not provided

• UV spectrophotometer (capable of measuring absorbance at 280 nm)
• Balance, weighing paper, scissors, mortar or homogenizer, centrifuge tubes, centrifuge, filter paper or gauze, quartz cuvettes
• Experimental materials: Peaches, plums, apples, apricots, or other fruits/plant tissues.  

Operating Steps (for reference only)

1. Total Phenol Extraction

1.1 Take fruit or other plant tissue, wash and dry it. Weigh 0.25 g of fresh, cut‑up sample and place it in a mortar or homogenizer pre‑cooled at 4°C.

1.2 Add 2–3 mL of TP Assay Buffer (pre‑cooled at 4°C). Grind or homogenize thoroughly, then transfer to a 10 mL centrifuge tube. Rinse the mortar/homogenizer with TP Assay Buffer and transfer the rinse to the tube. Adjust the final volume to 8 mL with TP Assay Buffer.

1.3 Incubate at 4°C in the dark for 20 minutes, shaking 2–3 times during incubation. Then filter into a centrifuge tube. Alternatively, centrifuge at 8000 rpm for 3 minutes. The filtrate (supernatant) is the crude total phenol extract.

2. Dilution of Total Phenol Standard Solution

Dilute the Total Phenol Standard (1 mg/mL) with TP Assay Buffer to obtain a Total Phenol Standard (50 μg/mL). Using clean centrifuge tubes or test tubes, perform serial dilutions according to the following table:

Tube No.	1	2	3	4	5	6
Total Phenol Standard (50 μg/mL) (mL)	0.1	0.2	0.3	0.4	0.5	0.6
TP Assay Buffer (mL)	0.9	0.8	0.7	0.6	0.5	0.4
Total Phenol Concentration (μg/mL)	5	10	15	20	25	30

3. TP Sample Addition

Set up blank, standard, and test tubes according to the table below. If the total phenol concentration in the sample is too high, reduce the sample volume or dilute appropriately before measurement. It is recommended to set up duplicate tubes for each sample and take the average.

Substance Added (mL)	Blank Tube	Standard Tube	Test Tube
TP Assay Buffer	1	—	—
Total Phenol Standard Series (Tubes 1–6)	—	1	—
Crude Total Phenol Extract	—	—	1

Note: If using a larger cuvette, proportionally increase all reagent volumes. In this case, the volume V₁ of crude extract used in the calculation formula should be adjusted accordingly.

4. TP Measurement

Transfer the solutions from each tube to 1‑cm path length quartz cuvettes. Within 5–15 minutes, zero the spectrophotometer with the blank tube and measure the absorbance of the standard series and test tubes at 280 nm.

5. Result Calculation

Using the total phenol standard series concentrations (5, 10, 15, 20, 25, 30 μg/mL) as the x‑axis and the corresponding absorbance values as the y‑axis, plot a standard curve. Then calculate the total phenol concentration (μg/mL) for each test tube.

For tissue samples:

Total Phenol (μg/g) = C × V_T × N / W

For liquid samples:

Total Phenol (μg/mL) = C × N

Parameter Explanation:

C: Total phenol concentration of the test tube obtained from the standard curve (μg/mL)

VT_T: Total volume of crude total phenol extract (mL) = 8

W: Fresh weight of the sample (g)

N: Dilution factor

Precautions

1. To avoid photodegradation of total phenols, perform operations in low light as much as possible, and keep grinding/homogenization time short.

2. Sample amount and reagent volumes should be adjusted appropriately based on the total phenol content.

3. TP Assay Buffer should be stored tightly sealed to prevent evaporation of active components.

4. During measurement, cover the quartz cuvette to prevent evaporation.

5. Measurements should be performed promptly. Prolonged delay, especially with high phenol concentrations, may result in underestimation.

6. When plant total phenol concentration is within 10–20 μg/mL, the OD value is relatively stable. Outside this range, results may change slightly over time.

7. If a UV spectrophotometer is unavailable, a full‑wavelength microplate reader can also be used.

8. For your safety and health, please wear a lab coat and disposable gloves during operation.

9. Please use the reagent as soon as possible after opening to avoid affecting subsequent experimental results.

Storage and Shipping

Storage

Store at 2-8°C,Protected from light,Room temperature

Shipped In

Wet ice

Stability And Storage

Each component has a shelf life of 1 year under corresponding storage conditions. P1509321A: Store at 2-8℃ long term (12 months). Store in the dark. P1509321B: Store at room temperature long term (12 months).  

Contents & Storage

P1509321	Component	50T	Storage
P1509321A	Total Phenol Standard (1 mg/mL)	1.5 mL	2-8℃. Store in the dark.
P1509321B	TP Assay Buffer	500 mL	RT.